This view of the twilight sky and Martian horizon taken by NASA's Curiosity Mars rover includes Earth as the brightest point of light in the night sky. Earth is a little left of center in the image, and our moon is just below Earth.

This frame from an animation from NASA's Mars rover Curiosity shows the rover drilling into rock target 'Cumberland.' The drilling was performed during the 279th Martian day, or sol, of the Curiosity's work on Mars (May 19, 2013).

This image from the Mars Hand Lens Imager on NASA's Mars rover Curiosity shows the patch of rock cleaned by the first use of the rover's Dust Removal Tool (DRT). The tool is a motorized, wire-bristle brush on the turret at the end of the rover's arm.

The two bodies in this portion of an evening-sky view by NASA's Mars rover Curiosity are Earth and Earth's moon. The rover's Mast Camera (Mastcam) imaged them in the twilight sky of Curiosity's 529th Martian day, or sol (Jan. 31, 2014).

This image maps the traverse of NASA's Mars rover Curiosity from 'Bradbury Landing' to 'Yellowknife Bay,' with an inset documenting a change in the ground's thermal properties with arrival at a different type of terrain.

From a position in the shallow 'Yellowknife Bay' depression, NASA's Mars rover Curiosity used its right Mast Camera (Mastcam) to take the telephoto images combined into this panorama of geological diversity.

This image from the Mars Hand Lens Imager on NASA's Mars rover Curiosity shows the patch of rock cleaned by the first use of the rover's Dust Removal Tool (DRT). The tool is a motorized, wire-bristle brush on the turret at the end of the rover's arm.

The sinuous rock feature in the lower center of this mosaic of images recorded by the NASA Mars rover Curiosity is called 'Snake River.' Curiosity gets a closer look at Snake River for before proceeding to other nearby rocks.

On Nov. 22, 2012, or sol 106, NASA's Mars rover Curiosity was near a location called 'Point Lake' for an overlook of a shallow depression called 'Yellowknife Bay' which is in the left third of this scene, in the middle distance.

In a shallow depression called 'Yellowknife Bay,' the NASA Mars rover Curiosity drove to an edge of the feature to record this view of the ledge at the margin and a view across the 'bay' during the 130th Martian day, or sol, (Dec. 17, 2012).

This map traces where NASA's Mars rover Curiosity drove between landing at a site subsequently named 'Bradbury Landing,' where the rover entered a shallow depression called 'Yellowknife Bay' on Sol 125 (Dec.12).

The NASA Mars rover Curiosity used its left Navigation Camera to record this view of the step down into a shallow depression called 'Yellowknife Bay.' The descent into the basin crossed a step about 2 feet high, visible in the upper half of this image.

This map traces where NASA's Mars rover Curiosity drove between landing at a site subsequently named 'Bradbury Landing,' and the position reached during the mission's 123rd Martian day, or sol, (Aug. 10, 2012).

Camera and robotic-arm maneuvers for taking a self-portrait of the NASA Curiosity rover on Mars were checked first, at NASA's Jet Propulsion Laboratory in Pasadena, Calif., using the main test rover for the Curiosity.

These images from the NASA Mars Reconnaissance Orbiter show several impact scars on Mars made by pieces of the NASA Mars Science Laboratory spacecraft that the spacecraft shed just before entering the Martian atmosphere.

This map shows where NASA's Mars rover Curiosity has driven since landing at a site subsequently named 'Bradbury Landing,' and traveling to an overlook position near beside 'Point Lake,' in drives totaling 1,703 feet (519 meters).